Improvement in exhaust-valves for steam and air cylinders



52 GEORGE wEsTINGHoUsE, 1r.

Vhnproyement' in Exhaust Valves for Steam anall Air Engines. y I

NG. 122,544. Patentedlan.9,1872.

STATES IMPROVEMENT IN EXHAUST-VALVES `FOR STEAM AND AIR CYLINDERS.

Specification forming part of Letters Patent No. 122,544, dated January9, 1872.

SPECIFICATION. To all whom it may concern:

Be it known that I, GnoRGE 'WEsTINGHoUsn, Jr., of Pittsburg, in thecounty of Allegheny and State lof Pennsylvania, have invented a new anduseful Improvement in Exhaust- Valves and Ports for Steam and AirCylinders; and I do hereby declare the following to be a full, clear,and exact description thereof, reference being had to the accompanyingdrawing making part of this specification, in which- Figures l and 2 aresectional views of my improvement in one form of its application, andshowing the double-ended receiving and exhaust valve in each of its twopositions; and Fig. 3 is a detached perspective View of such valve. I

Like letters of reference indicate like parts in each.

My improved exhaust is more particularly designed for use in connectionwith the brakecylinders of steam-power air-brakes; and I will Iirstdescribe its construction and operation in sucli use, so as todistinguish the same from other known means of like character, and alsoenable others skilled in the art to make and use the same.

In such brakes air is compressed into, or when compressed is admittedinto, a brakecylinder, A, at such point with reference to a pistontherein that, by the movement of the piston, the brake-shoes will beapplied to the wheels. To relieve or let off77 the brakes it has beencommon to turn a cock at the engine and let the compressed air escape atthat point. This, in a long train, requires an appreciable interval oftime, which it is desirable to avoid. I hence have devised arelief orexhaust valve of such construction that when the air is discharged fromthe brake-pipes the valve will, by the pressure of the air in thecylinder, be opened at the cylinder and the compressed air be allowed toescape directly from each cylinder, instead of having Iirst to pass theentire length of the train, as heretofore. From the compressed air pipe,which extends back through the train under the cars, a branch pipe, B1,leads to the valve-case B. This valveca-se is open at both ends, and hasan enlarged valve-chamber, B2, from which an air-pipe or port, A', leadsto the brake-cylinder A. The outer ends of the valve-case B are closedby screw-nuts C C', the nut C being at the airentrance end, and theother, C', at the exhaust end. rIhe valve-chamber B2 is made of a littleshorter diameter at the exhaust end than at the other. Under the nut Cis a packingring, c, of India rubber or other suitable material, andunder the other nut, Cf, is a like ring, c, both resting on shoulders inthe valvecase, and held in place by their respective nuts, as shown, andboth having' central openings, through which air can enter and leavechamber B2. In this chamber I arrange a double-ended piston-valve, morefully shown in Fig. 3. 0n the opposite ends of a stem, I), I attach thepiston-valves D1 D2, the valve l)1 at the air-entrance end being alittle larger than the other, and the entire length from outside tooutside being a little less than the length of the chamber B2 betweenthe packing-rings c c. rIhe valve D1 has a series of holes, d d, throughwhich the air can pass in entering the chamber B2, and these holes orair-ports are opened or closed by means of a valve-plate, e, which isloosely arranged on the stem D, and is pressed against or toward thepiston D1 by means of a spring, e. The other valve has a similar seriesof air-exhaust holes, or, as shown, its periphery is notched orserrated, as at b, for the egress of air, the projections b between thenotches acting as guides in the chamber B2 to keep the valve in line.Its lower face has an annular ring a, V- shaped in cross-section thebetter to enable it to make an air-tight joint when seated on its gasketc.

The operation is as follows: When it is desired to apply the brakes thecompressed air is admitted, as illustrated by arrows in Fig. l, by thepipe B1 through the gasketc and airports d against the face of thevalve-plate c, which valve-plate is raised or forced back by thepressure, so that the air passes on into the chamber B2 and by the portAl into the brakecylinder A, where it does its work. The other valve, Dl, is at the same time, by the pressure ofthe air, seated on its gasketc'. When the brakes are to be released and the train started, connectionwith the air-reservoir is cut off and the air allowed to escape from thepipes which extend through the train. The eiect then is that the springc forces the valve-plate c against the valve D1 and closes the ports al.Also the compressed air in the chamber B2, exercising a greater forceagainst the larger valve D1, causes it to be seated on its gasket c,whereby the other valve D2 is raised clear of its gasket c', when thedevices are in the position shown in Fig. 2. The air then passes outfreely, as indicated by arrows, from the cylinder A, chamber B2, throughthe notches b, gasket c', and nut C', and so escapes almost instantly.The opening and closing of the inlet and exhaust ports are thusautomatically effected. The valve D1 acts in part as a checkvalve and inpart as a lifting device to the It it is desired to let oft' the brakesonly in part, it may be done by letting out of the brake-pipes only aportion of the compressed air contained in them and then closing thecock. The air will in such case pass out from the cylinder through theexhaust until the pressure in the cylinder falls a little below thereduced pressure in the pipes, and then the exhaust-valve D2 will be andremainseated. In this Way the force with Which the brake-shoes areapplied to the Wheels may be graduated at pleasure. The valve-plate eand spring e may be dispensed With, and the ports d be closed by thevalve C coming against the gasket c; but this construction renders itnecessary to make the ports d smaller than would otherwise be necessary;and in applying the brakes large air-entrance ports are desirable. Thesaine devices are applicable in use as an exhaust for air, gas, steam,and water cylinders generally, with only such variations in theirarrangement with reference to the cylinders aswill readily suggestthemselves to the skilled mechanic, and such uses I include among otherpurposes of my invention.

What I claim as niy invention, and desire to secure by Letters Patent,is

1. A double-ended piston-valve having ends of different areas exposed toan inside pressure, provided With,-I inlet-ports at one end andexhaust-ports at the other alternating in use, substantially as and forthe purposes set forth.

2. The doubleended piston-valve of the preceding claim in combinationwith a cylinder from which the power is to be applied, substantially asdescribed.

3. An exhaust-valve, D2, lifted from its seat by the pressure andagainst'the pressure of the duid to be exhausted, substantially asdescribed.

4. The valves D1 D2 arranged on a single stem, in combination with thevalve-platee and spring e, substantially as set forth.

In testimony whereof I, the said GEORGE WEs'rINGHoUsE, Jr., havehereunto set my hand.

